\documentclass{article}
\usepackage[usenames,dvipsnames]{xcolor}
\usepackage{tcolorbox}
\usepackage{tabularx}
\usepackage{array}
\usepackage{colortbl}
\tcbuselibrary{skins}

\newcolumntype{Y}{>{\raggedleft\arraybackslash}X}

\tcbset{tab1/.style={fonttitle=\bfseries\large,fontupper=\normalsize\sffamily,
colback=yellow!10!white,colframe=red!75!black,colbacktitle=Salmon!40!white,
coltitle=black,center title,freelance,frame code={
\foreach \n in {north east,north west,south east,south west}
{\path [fill=red!75!black] (interior.\n) circle (3mm); };},}}

\tcbset{tab2/.style={enhanced,fonttitle=\bfseries,fontupper=\normalsize\sffamily,
colback=yellow!10!white,colframe=red!50!black,colbacktitle=Salmon!40!white,
coltitle=black,center title}}

\begin{document}

\begin{tcolorbox}[tab2,tabularx={X||Y|Y|Y|Y||Y}]
Group & One     & Two     & Three    & Four     & Sum      \\\hline\hline
Red&1000.00&2000.00&3000.00&4000.00&10000.00\\\hline
Green&2000.00&3000.00&4000.00&5000.00&14000.00\\\hline
Blue&3000.00&4000.00&5000.00&6000.00&18000.00\\\hline\hline
Sum&6000.00&9000.00&12000.00&15000.00&42000.00
\end{tcolorbox}

\begin{tcolorbox}[tab2,tabularx={X||Y|Y|Y|Y||Y},title=My table,boxrule=0.5pt]
Group&One&Two&Three&Four&Sum\\\hline\hline
Red&1000.00&2000.00&3000.00&4000.00&10000.00
\Green&2000.00&3000.00&4000.00&5000.00&14000.00
\Blue&3000.00&4000.00&5000.00&6000.00&18000.00\\\hline\hline
Sum&6000.00&9000.00&12000.00&15000.00&42000.00
\end{tcolorbox}

\begin{tcolorbox}[tab1,tabularx={X||YYYY||Y}]
Group&One&Two&Three&Four&Sum\\\hline\hline
Red&1000.00&2000.00&3000.00&4000.00&10000.00
\Green&2000.00&3000.00&4000.00&5000.00&14000.00
\Blue&3000.00&4000.00&5000.00&6000.00&18000.00\\\hline\hline
Sum&6000.00&9000.00&12000.00&15000.00&42000.00
\end{tcolorbox}

\end{document}
